Evaluate the definite integral. $\int^{-1}_{-2}15x^{-4}\,dx = $
Solution: First, use the power rule: $\int^{-1}_{-2}15x^{-4}\,dx ~=~-5x^{-3}\Bigg|^{-1}_{{-2}}$ Second, plug in the limits of integration: $[-5\cdot({-1})^{-3}]-[-5\cdot({-2})^{-3}] = 5-0.625 = 4.375$. The answer: $\int^{-1}_{-2}15x^{-4}\,dx = 4.375$